Thought I'd post some pictures of my recent experience repairing soft spots, so that others may hopefully avoid the same pitfalls. I'm sure it pains the H18 old salts to see a newbie doing irreparable damage to their hulls, but it is what it is. Hopefully the repair will still hold and last for a long time!

I bought my boat ('79) used two years ago, and at the time I bought it, I did not find any soft spots. Last year, I found that I had two: one on the aft deck of each hull, aft of the rear crossbar. Seems like a very odd place to me... and the port soft spot especially seemed to appear suddenly.

I attempted the soft spot repair on the starboard hull last year and the port hull this year. The starboard side was about a 6" circle, the port side was the entire aft deck, lip to lip, almost to the rear crossbar (but not quite). After having completed the repair, I filled the holes with matched gel coat and sanded it down. The starboard side looks fantastic.

The port side looks sloppy, but I had a lot of holes, most of which were in the non-skid (84 on port, 17 on starboard).

I'm a bit disappointed, but at least it's fixed.

The starboard side took almost 16oz of epoxy to fill. It was a lot for a small area, so I was suspicious. When the port side took half as much, I knew I was in trouble. I had planned to add deck ports this year anyways, so I was curious to see what it looked like. After cutting the holes, I found that the starboard side leaked through, leaving a puddle of cured epoxy inside my hull. (pardon the dust)

Apparently it seeped through the inner layer of fiberglass? Or perhaps it was cracked?

All of the fill holes were aft of my deck port location on the starboard hull, but it appears the epoxy did extend forward of the deck port hole. There is a separation in the lip right at the rear crossbar, so perhaps that's how the air was escaping?

looking aft:

looking forward (above deck):

looking forward (below deck):

After my experience with repairing the soft spot on the starboard side, I was expecting to need much more epoxy on the port side. It was a huge area, and made a loud "crunch" whenever pressed on. I ended up over filling it, and it ballooned out. The top side is somewhat "wavy", so I knew I had over filled it a bit. I just had no idea how much until I cut the hole for the deck port.

looking forward:

looking aft:

As you can see, I also wound up with large air pockets in the epoxy. I believe this to be because I didn't continuously fill from the same hole the entire time. The repair seemed too big for the epoxy to spread continuously throughout the area from the same hole. So when one fill hole started to get difficult and ooze back out, I moved on to the next one. I knew this was a bad idea, but I didn't know what else I could do. I was a bit overwhelmed by the size of the damaged area.

I was, however, surprised to see that the foam had not rotted out, that the soft spot was just separation between the foam and the fiberglass. With how large and soft the spot was and how loud it crunched, I was sure that the foam was gone. Thinking that the epoxy needed to take up the void that the foam left behind also lead me to over-fill the void.

The starboard hull repair, which was done "right" as far as I can tell (minus the extra epoxy in the hull), was all filled from one hole, until epoxy started coming out of all of the surrounding holes. Then I covered the fill hole and moved on to the next hole (where epoxy had just started oozing out of) with the same process. When the epoxy began oozing out of the perimeter holes, I covered them to force the epoxy to fill to the next hole. I tried to use this same approach on the port side, but I may have rushed it, worried about the epoxy kicking before I finished filling the soft spot. I also drilled my holes too far out on the port side. Make sure you drill your holes just INSIDE of the perimeter of the soft spot. Mine were just outside of it, so I had to re-drill a number of them, which of course just added to the mahem as we were trying to mix, drill and inject all at the same time.

Oh well, live & learn, I suppose. Nothing I can do about it now. Both repairs are very solid, though I'm sure they're also quite heavy. Anybody with more experience fixing soft spots care to comment? Anything else I could've done or should've done? Anything that you recommend moving forward? Any way to get rid of that puddle of epoxy?

The most important thing is to bond the inner layer of glass back to the foam, and it looks like you achieved that. It's not a "perfect" process, but it's a heck of a lot easier than removing and replacing an entire section of the deck. I don't think the voids in the epoxy are really an issue. The main issue with the "bulged" area is that you ended up using more resin than you needed, so a little extra weight, but I think the strength is probably fine, especially for that area of the hull.

The best way to remove the pooled resin in the bottom of the hull would be to grind it out with a dremel tool or an abrasive disk and then vacuum up the dust. Also, in the future, I would put masking tape across the entire area where you're going to inject and then drill your holes through the tape and into the hull. This way excess resin ends up on the tape and not the hull. You were correct in pumping resin into all the different holes. You want to work your way around the area, pumping into each of the holes until the resin flows out of the adjacent holes. Once you're satisfied that everything is saturated with resin, wipe up the excess epoxy, then remove the tape, and wipe up any resin that may have gotten on the hull using an acetone soaked towel.

Thanks sm. I was kinda wondering if the bulging of the repair was inevitable due to the size of the area and how thin the inner layer of glass is.

I did actually tape off the entire repair area beforehand. I'm very glad I did, the epoxy really makes a mess atop the hulls! A little epoxy got underneath the tape, but for the most part it made the cleanup a lot easier. There's a little that got in the non-skid and hardened, unfortunately, but it's not too terribly noticeable. I do think I got a little carried away trying to sand the new gel coat flush, and after seeing just how thin it is at the cut out, I'm very glad I stopped when I did!

edit:

On second glance, I think what you're interpreting as epoxy in the non-skid is actually the gelcoat that I tried to patch the holes with. If you don't catch a the glare/reflection off the deck, the patches blend right in. Like I said, it looks kinda sloppy, but I think it looks better than all the dark and obvious looking holes in the deck!

_________________Mike'79 H18 standard 'Rocketman II' sail #14921

Last edited by SabresfortheCup on Mon Jun 09, 2014 6:40 pm, edited 1 time in total.

What kind of epoxy did you use? Wonding if the thinner git-rot would of avoided bulging out the inner skin. Looks like ya did good to me though. I just fixed a small area on my faded light blue 1980 16. I dont even try to matcht he gel coat anymore. Just want the boat solid.

Thanks! I used West System's 105 epoxy, 206 hardener and a combination of the 406 and 407 fillers (colloidal silica and low density filler). Not sure if Git-rot would've avoided it. I think the separation was so large and the epoxy was so heavy that it was bound to happen, especially with the amount we injected in. it was tough to inject at first, but by the time we were done a couple of the holes were really flowing back out.

Yeah... too much pressure applied, forces the layers apart. I still stick ( ) by GitRot for this application as it penetrates and seeps into voids, but you still have to be careful not to force too much in. Not sure it would have helped the porous inner layer issue though.

You ask what you could have and should have done, Its done, the boat is solid.

You are absolutely right! The boat is fixed, and I have no regrets in that regard. I'm just a perfectionist, and like to know how close I got to the "right" way to do it

But I've learned a lot through these forums, and I wanted to find out if there's anything different others would have done, in case I ever need to do it again.

I hope that others can learn from it as well. At the very least, it provides some interesting cross sections. Not many people cut into a repaired soft spot! The fiberglass and gelcoat layers are much thinner than I expected, and the anatomy of the soft spot is also not what I expected. Given how soft the port hull felt, I really thought the foam was gone. I wouldn't have guessed that just a little separation could cause so much fuss!

Mike,I attempted a port deck repair last year. A soft spot just in front of the crossbar. I used Git Rot, largely due to the recommendations found here and for it lower viscosity. After pumping in an entire bottle with none of it coming up the breather holes, I knew I had trouble with cracked lower fiberglass layer.

The good news was the Git Rot that pooled in the hull bottom easily pulled right out, which is why I was asking the release wax question in the other thread.

Then I understand your concern! Certainly seems odd... mine isn't pulling out, that's for sure. The only place that I was able to break it out was where the remnants of the plastic bag were sitting (the bag that used to contain the foam blocks deteriorated, and was in pieces near the transom). If only it had been a little further forward, it could've saved me quite a mess!

I ended up over filling it, and it ballooned out. The top side is somewhat "wavy", so I knew I had over filled it a bit. I just had no idea how much until I cut the hole for the deck port.

I also have done injections on the main deck and rear and find the final result to be ""WAVY"". I'm wondering if the glue as is cures is not expanding. The process is to fill the voids until it weeps out a breather hole.

For me I have been using TAP Plastic's Marine Grade Epoxy System in a 2 to 1 mix. When mixed it has a low viscosity and flows well.Side A 314 Resin ($87.95 per gallon)Side B 143 Hardener Slow ($59.65 per half gallon)